超临界CO_2萃取芫荽籽油的数学模型

Research on the Mathematical Model of the Extraction of Coriander Seed Oil with Supercritical Carbon Dioxide Fluid

[目的]优化超临界CO2萃取芫荽籽油的工艺条件。[方法]通过单因子试验考察萃取压力、CO2流量、萃取时间以及萃取温度对芫荽籽油萃取率的影响。利用MATLAB软件,对试验数据进行多元多项式拟合。[结果]对纯粹二次拟合模型进行拟合可信度的F检验,结果表明多项式各项对y线性关系极显著(P<0.01),从而确定萃取压力、CO2流量、萃取时间以及萃取温度对萃取率影响的较为合理的拟合模型为纯粹二次多项式模型。将上述二次多项式代入MATLAB的无约束最优化工具,计算出超临界CO2萃取芫荽籽油的最佳工艺条件是:萃取压力21.84MPa,CO2流量33.26 L/h,萃取时间142.90 min,萃取温度42.6℃,该条件下最佳萃取率为12.61%。[结论]超临界CO2萃取芫荽籽油工艺中,萃取压力、CO2流量、萃取时间、萃取温度对萃取率的影响是相互独立的,通过对各工艺条件的改变可以大幅度提高芫荽籽油萃取率。

[Objective] The process condition of the extraction of coriander seed oil with the method of supercritical carbon dioxide fluid was optimized.[Method] The effect of the extracting pressure,time and temperature,the rate of CO2 flow,on the yield of coriander seed oil based on the method was investigated through the single factor experimental design.The experimental data was fitted in multiply-element and multiply-item/polynomial by means of MATLAB software.[Result] The reliability of the purely quadratic fitting model was done with F-test and the testing results showed that the item of multiply-item/polynomial was significant with the y linear relationship with（P0.01）,so it was determined that more reasonable fitting model of the effect of the extraction pressure,the flow rate of carbon dioxide,the extraction time and the extraction temperature on the extraction rate was the purely quadratic multiply-item/polynomial model.After the quadratic multiply-item/polynomial was put into the unconstrained optimization tool of MATLAB,the optimum condition of the extraction of coriander seed oil with the method of supercritical carbon dioxide was calculated： the extraction pressure was 21.84 MPa,the rate of CO2 flow,33.26 L/h;the extraction time,142.90 minutes and the extraction temperature,42.6 ℃,under which condition,the extraction yield was 12.61%.[Conclusion] In technique of the coriander seed oil with the method of supercritical carbon dioxide,the individual of each factor： the extraction pressure,the rate of carbon dioxide flow,the extraction time and the extraction temperature could affected the extraction rate and the technical improvement in the process could significantly result in the change of the extraction rate of coriander seed oil.